Doug,
I have
a little experience in this area, if you recall.
![Roll Eyes Roll Eyes](https://westernbassclub.com/yabbfiles/Templates/Forum/default/rolleyes.gif)
You won't find a boat repair place anywhere in the state that will tackle this, but a few well-placed calls to welding shops will do the trick. You'll need to bring the boat in for them to assess the work, and they'll all have differing opinions/rates on what it will take. No single way is the "right way", just the one that's the best option within your budget.
The larger issue is that the aluminum around the crack has thinned and weakened. Thus making it difficult to repair (there's not much aluminum to work with). Worse yet, the repair may only be temporary if this isn't taken into consideration - tears will appear around the repair in no time.
The solution for my boat was to weld up the 2' rips in the hull, then reinforce the areas by tack-welding aluminum angle iron over the weld, extending well beyond it, and then sealing it into place with Sikaflex 292.
The welder was very good and did not need to remove the foam. He was slow, cautious, and methodical. The foam melted around the holes he repaired, but the reinforcement made up for it.
As for the rivets - I went to a machine shop supply store and got some solid-core rivets and replaced every stinkin' leaking rivet (28 of them!), dabbing them in FAA approved aircraft sealant before installing them.
The end result? It was a bullet-proof, leak-proof tank. All for under $500.